Étiqueté : transmission

Les bien-portants, dits « asymptomatiques » ne transmettent pas le Covid19 : étude chinoise sur 10 Millions de personnes © Pixabay 0

Les bien-portants, dits « asymptomatiques », ne transmettent pas le Covid19 : étude chinoise sur 10 millions de personnes !

Depuis le début de l’épidémie de Covid19, les modes précis de la transmission et le rôle des asymptomatiques dans celle-ci font débat. Cette dernière question vient d’être tranchée par l’analyse d’un étude chinoise géante de Wuhan qui démontre que les asymptomatiques ne contaminent personne.

Figure 1. Identification of the possible source of infection and analysis of viral genomes obtained in the outbreak © The Author(s) 0

Cold-chain food contamination as the possible origin of Covid-19 resurgence in Beijing

Covid-19, caused by SARS-CoV-2, has been contained in China through stringent non-pharmaceutical interventions. The border control and quarantine have effectively prevented the virus spread by infected travellers, but the risk of resurgence caused by other routes of introduction and transmission remains unclear, and current strategies to prevent resurgence could be flawed. Since July, SARS-CoV-2 RNA contaminations in frozen food imported from countries with ongoing epidemics have been reported in nine provinces in China. However, there is no robust evidence of Covid-19 outbreaks initiated by environment-to-human transmission. Here we add to evidence of such transmission by investigating the recent Covid-19 resurgence in Beijing.

Capture d'écran du reportage " Coronavirus : le saumon, victime collatérale de la crise en Chine". © Le Point.fr 0

[Chine] Pas de preuve d’une transmission par les aliments (expert)

BEIJING, 19 juin (Xinhua) — Aucune preuve n’a été découverte concernant la transmission du nouveau coronavirus par l’ingestion d’aliments, dont les fruits de mer, a indiqué vendredi un épidémiologiste chinois, en réponse aux préoccupations du public concernant la sécurité des produits frais.

Figure 1Spatial distribution of COVID-19 case clusters on the basis of contact tracing data from Guangzhou, China, from Jan 7, 2020, to Feb 18, 2020 @ DR / The Lancet / Elsevier Ltd 0

Household secondary attack rate of COVID-19 and associated determinants in Guangzhou, China: a retrospective cohort study

As of June 8, 2020, the global reported number of COVID-19 cases had reached more than 7 million with over 400 000 deaths. The household transmissibility of the causative pathogen, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains unclear. We aimed to estimate the secondary attack rate of SARS-CoV-2 among household and non-household close contacts in Guangzhou, China, using a statistical transmission model.

Le Dr Cheng Hao-yuan [鄭皓元] (à d.) du CDC de Taiwan a présenté le 2 mai lors de la conférence de presse du Quartier général de lutte épidémique (CECC) l’étude publiée la veille dans JAMA Internal Medicine. © CNA 0

Une étude taiwanaise sur la transmission du Covid-19 publiée dans la revue JAMA Internal Medicine

Une étude menée sur les 100 premiers cas confirmés de Covid-19 à Taiwan ainsi que sur leurs contacts proches a été publiée le 1er mai dans le prestigieux Journal of the American Medical Association (JAMA) Internal Medicine. Elle confirme que le risque de transmission du coronavirus à ses proches est le plus élevé pendant les cinq jours suivant l’apparition des symptômes, mais aussi avant même leur apparition.

Attack rate among close contacts, baseline severity, and proportion of cases without fever at initial assessment by age group . © The lancet 0

Epidemiology and transmission of COVID-19 in 391 cases and 1286 of their close contacts in Shenzhen, China: a retrospective cohort study

Rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Wuhan, China, prompted heightened surveillance in Shenzhen, China. The resulting data provide a rare opportunity to measure key metrics of disease course, transmission, and the impact of control measures.

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Sur les traces du pangolin

La transmission du virus SARS-CoV-2 de l’animal à l’homme reste actuellement une question en suspens sans réponse précise. L’intervention du pangolin comme hôte intermédiaire a été souvent soulignée par les scientifiques sans être confirmée. La recherche du chainon manquant de la transmission permettrait de retracer la généalogie et la génétique du virus. Nous vous présentons une sélection d’articles sur cet animal sauvage méconnu du grand public avant la pandémie et placé aujourd’hui sous les feux de l’actualité. Les recherches en cours nous dirons si cette piste est la bonne…

couverture de la revue Journal of Medical Virology. 0

Potential of large “first generation” human‐to‐human transmission of 2019‐nCoV

To investigate the genetic diversity, time origin, and evolutionary history of the 2019‐nCoV outbreak in China and Thailand, a total of 12 genome sequences of the virus with known sampling date (24 December 2019 and 13 January 2020) and geographic location (primarily Wuhan city, Hubei Province, China, but also Bangkok, Thailand) were analyzed. Phylogenetic and likelihood‐mapping analyses of these genome sequences were performed. On the basis of our results, the star‐like signal and topology of 2019‐nCoV may be indicative of potentially large “first generation” human‐to‐human virus transmission. We estimated that 2019‐nCoV likely originated in Wuhan on 9 November 2019 (95% credible interval: 25 September 2019 and 19 December 2019), and that Wuhan is the major hub for the spread of the 2019‐nCoV outbreak in China and elsewhere. Our results could be useful for designing effective prevention strategies for 2019‐nCoV in China and beyond.

Panel B - Date through which data were used to estimate R. © Majumder, Maimuna and Mandl, Kenneth D. 0

Early Transmissibility Assessment of a Novel Coronavirus in Wuhan, China

Between December 1, 2019 and January 26, 2020, nearly 3000 cases of respiratory illness caused by a novel coronavirus originating in Wuhan, China have been reported. In this short analysis, we combine publicly available cumulative case data from the ongoing outbreak with phenomenological modeling methods to conduct an early transmissibility assessment. Our model suggests that the basic reproduction number associated with the outbreak (at time of writing) may range from 2.0 to 3.1. Though these estimates are preliminary and subject to change, they are consistent with previous findings regarding the transmissibility of the related SARS-Coronavirus and indicate the possibility of epidemic potential.

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